Immunological changes associated with post-surgical gram-negative bacterial infections

Objective: Post-surgical bacterial infections provoke immune responses mediated by various cytokines. This study aimed to assess immunological changes by measuring serum levels of IL-2, IL-7, IL-10, and IL-17 in post-surgical patients with bacterial infections and comparing them with non-infected post-surgical patients and healthy controls. Methods: In this prospective, single-centre investigation, we analysed serum cytokine levels across three distinct groups: (1) patients with post-surgical bacterial infections, primarily involving Klebsiella pneumoniae; (2) non-infected post-surgical patients (surgical controls); and (3) healthy individuals (baseline controls). Serum cytokine levels were measured using ELISA. Statistical analysis was performed using one-way ANOVA to identify group differences, and ROC curve analysis was used to evaluate diagnostic performance. Results: Serum analysis revealed significantly elevated levels of all measured cytokines in post-surgical patients with bacterial infections compared to surgical controls and healthy individuals (p < 0.001). IL-2 levels reached 363.6 ± 38.5 pg/mL in infected patients, compared to 225.8 ± 24.5 pg/mL in non-infected post-surgical patients and 151.6 ± 24.4 pg/mL in healthy controls. Similarly, IL-7, IL-10, and IL-17 levels were substantially higher in infected individuals. ROC analysis showed excellent diagnostic accuracy, with IL-2 and IL-10 demonstrating an AUC of 1.000. Conclusion: Post-surgical bacterial infections lead to clear immunological changes. Cytokine profiling, particularly that of IL-2 and IL-10, could serve as a biomarker for early detection and better treatment of these infections. These observations indicate that IL-2 and IL-10 could potentially act as reliable biomarkers for the early detection and ongoing assessment of infections following surgery.